1. Field of the Disclosure
The present invention relates to a printing apparatus and method for forming a thin film pattern using the printing apparatus which can form a multi-layered thin film pattern on a substrate.
2. Discussion of the Related Art
Recently, various kinds of flat display devices have been developed, which can reduce weight and volume that are disadvantages of a cathode ray tube. As the flat display device, there are a liquid crystal display device, a field emission display device, a plasma display panel, an electroluminescence EL display device, and so on.
The flat display device is provided with a plurality of thin films formed by mask process including a deposition step, an exposure step, a development step, and etching step, and so on. However, since the mask process as a complicate fabrication process, the mask process increases a production cost. Consequently, researches for forming the thin film by using a printing process utilizing a blanket roller are under progress.
The printing process is a process in which printing ink is coated on a blanket of a blanket roller, a pattern of the printing ink is formed on the blanket roller by using a printing plate, and the pattern of the printing ink is transcribed to a substrate, thereby forming a desired thin film.
In this instance, if a metal film of silver Ag is formed by using ink having silver Ag powder dispersed therein, there has been a problem in that the metal film of silver is separated from the substrate due to low adhesive force between silicon contained in the substrate and the silver.
In order to solve the problem, if the metal film is formed of printing ink having a metal which has good adhesive force to the substrate and the silver powder added thereto, dispersion stability of the ink is broken easily due to reaction among dispersion binders which are different for every metal.